First, we clarify the questions of whether a sensor can also be tested without a device. First of all: yes ;-
And how can we convert the voltage into a temperature

Published March 1, 2020

Temperature Sensing with TMP36

This sensor is a good start for beginners: analog read > temperature.

BeginnerProtip30 minutes20,326

Things used in this project

Hardware components

Temperature Sensor

Breadboard (generic)

Jumper wires (generic)

3 pieces

Arduino Nano R3

Software apps and online services

Arduino IDE

Story

We are dealing with the TMP36 from Analog Devices - here is the datasheet.

First, we clarify the questions of whether a sensor can also be tested without a device. First of all: yes ;-)

Then we look at the method of how to convert the voltage into the temperature.

Power Station

Apply 2.7-5.5V to the left leg via batteries or another power source. Connect the right leg to GND (2-4 AA batteries work fantastic). The writing on the sensor is facing you. The semicircular circle lies on the floor.

test the sensor

The voltage is measured over the middle leg: use a multimeter and connect GND with GND and use the red reading head of the multimeter to read the voltage on the middle leg.

My comfortable room temperature is apparently 0.718 volts.

voltage measureing

You can safely touch the sensor with your fingers or hold it under a heat-emitting lamp: the voltage value changes immediately.

And how can we convert the voltage into a temperature?

Nano is reading TMP36

If you're using a 5V Arduino, and connecting the sensor directly into an Analog pin, you can use these formulas to turn the 10-bit analog reading into a temperature:

Voltage at pin in milliVolts = (reading from ADC) * (5000/1024)This formula converts the number 0-1023 from the ADC into 0-5000mV (= 5V)

//getting the voltage reading from the temperature sensor
int reading = analogRead(sensorPin);
// converting that reading to voltage, for 3.3v arduino use 3.3
float voltage = reading * 5.0;
voltage /= 1024.0;
// print out the voltage
Serial.print(voltage); Serial.println(" volts");

If you're using a 3.3V Arduino, you'll want to use this:

Voltage at pin in milliVolts = (reading from ADC) * (3300/1024)This formula converts the number 0-1023 from the ADC into 0-3300mV (= 3.3V)

Then, to convert millivolts into temperature, use this formula:

Centigrade temperature = [(analog voltage in mV) - 500] / 10

// now print out the temperature
float temperatureC = (voltage - 0.5) * 100 ;  //converting from 10 mv per degree with 500 mV offset
//to degrees ((voltage - 500mV) times 100)
Serial.print(temperatureC); Serial.println(" degrees C");

Don't be confused: whether you calculate 0.5 x 100 or 500/10 leads to the same result.

The results can be viewed on the serial monitor of the Arduino IDE with 9600 baud.

You can find more information here at Adafruit.

TMP36

    //TMP36 Pin Variables
    int sensorPin = 0; //the analog pin the TMP36's Vout (sense) pin is connected to
                       //the resolution is 10 mV / degree centigrade with a
                       //500 mV offset to allow for negative temperatures
     
    /*
     * setup() - this function runs once when you turn your Arduino on
     * We initialize the serial connection with the computer
     */
    void setup()
    {
      Serial.begin(9600);  //Start the serial connection with the computer
                           //to view the result open the serial monitor 
    }
     
    void loop() // run over and over again
    {
     //getting the voltage reading from the temperature sensor
     int reading = analogRead(sensorPin);  
     
     // converting that reading to voltage, for 3.3v arduino use 3.3
     float voltage = reading * 5.0;
     voltage /= 1024.0; 
     
     // print out the voltage
     Serial.print(voltage); Serial.println(" volts");
     
     // now print out the temperature
     float temperatureC = (voltage - 0.5) * 100 ;  //converting from 10 mv per degree with 500 mV offset
                                                   //to degrees ((voltage - 500mV) times 100)
     Serial.print(temperatureC); Serial.println(" degrees C");
     
     // now convert to Fahrenheit
     float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;
     Serial.print(temperatureF); Serial.println(" degrees F");
     
     delay(1000); //waiting a second
    }

Credits

Ingo Lohs

182 projects • 199 followers

I am well over 50 years and come from the middle of Germany.

Temperature Sensing with TMP36

Things used in this project

Hardware components

Software apps and online services

Story

First, we clarify the questions of whether a sensor can also be tested without a device. First of all: yes ;-)

And how can we convert the voltage into a temperature?

Code

TMP36

Credits

Ingo Lohs

Comments

Embed the widget on your own site

Temperature Sensing with TMP36

Temperature Sensing with TMP36

Things used in this project

Hardware components

Software apps and online services

Story

First, we clarify the questions of whether a sensor can also be tested without a device. First of all: yes ;-)

And how can we convert the voltage into a temperature?

Code

TMP36

Credits

Ingo Lohs

Comments

Related channels and tags